Specific Promoter CpG Island Methylation Patterns Identify Different Subgroups of MLL - Rearranged Infant Acute Lymphoblastic Leukemia, and Define Clinical Outcome

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 596-596 ◽  
Author(s):  
Dominique Jpm Stumpel ◽  
Pauline Schneider ◽  
Eddy HJ van Roon ◽  
Judith M Boer ◽  
Renee X Menezes ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Bone Marrow ◽  
Cpg Island ◽  
Expression Profiles ◽  
Lymphoblastic Leukemia ◽  
Gene Expression Profiles ◽  
Relapse Free Survival ◽  
Free Survival ◽  
Methylation Patterns

Abstract At present, long-term survival rates in childhood acute lymphoblastic leukemia (ALL) easily exceed 80%. However, the prognosis for infants (<1 year) with ALL barely reaches 50%. Infant ALL is characterized by chromosomal translocations involving the Mixed Lineage Leukemia (MLL) gene that occur in about 80% of the cases. The most frequent MLL translocations in infant ALL include t(4;11), t(11;19) and t(9;11). In about 20% of the infant ALL cases no MLL rearrangements are observed. Recent gene-expression profiling characterized MLL-rearranged ALL as a unique type of leukemia, that is genetically clearly separable from other ALL subtypes. As epigenetic modifications affect gene-expression, we hypothesized that the specific gene-expression profiles associated with MLL-rearranged ALL may well be driven by epigenetic changes. The best-studied epigenetic event in hematological malignancies constitutes the transcriptional silencing of (tumor suppressor) genes by promoter CpG island hypermethylation. To explore the DNA methylation patterns underlying MLL-rearranged infant ALL, we applied Differential Methylation Hybridization (DMH) using both 9k (Huang, 2002) and 244k CpG island microarrays (Agilent) on primary infant ALL samples carrying t(4;11) (n=21), t(11;19) (n=17), t(9;11) (n=6) or wild-type MLL genes (n=13). The resulting DNA methylation patterns were compared with the patterns found in healthy pediatric bone marrow samples (n=8). In addition, relapse material from three infants with MLL-rearranged ALL was included and compared with the corresponding patient sample obtained at diagnosis. Both CpG island microarray platforms demonstrate that t(4;11) and t(11;19) characterize extensively hypermethylated leukemias, whereas t(9;11)-positive and translocation-negative infant ALL epigenetically resemble normal bone marrow. When the CpG array data (Agilent) were compared with available gene expression profiles (Affymetrix), we found that 95% of the genes from the top 100 of genes most significantly hypermethylated in t(4;11)- or t(11;19)-positive infant ALL were indeed down-regulated. Using the t(4;11)-positive cell line models SEMK2 and RS4;11, we demonstrate that the majority of these hypermethylated genes could be demethylated by the demethylating agent zebularine. Among t(4;11)- and t(11;19)-positive infant ALL samples, two subgroups could be identified displaying either more or less pronounced methylation patterns. Heavy methylation appeared to be associated with a significantly reduced relapse-free survival (p=0.03). Encouraged by these data, we analyzed relapse samples from t(4;11)- and t(11;19)-positive infant ALL patients, and found that these samples were even more extensively hypermethylated than the corresponding initial infant ALL samples. We here present, for the first time to our knowledge, a global view of the methylome in infant patients with MLL-rearranged ALL. We demonstrate that severe promoter CpG hypermethylation is present in t(4;11)- and t(11;19)-positive infant ALL. Of main therapeutic interest is our finding that the degree of DNA methylation among t(4;11)- and t(11;19)-positive infant ALL patients is related to relapse-free survival. Therefore, MLL-rearranged infant ALL patients with heavily methylated leukemias in particular should be considered candidates for therapies including inhibitors of DNA methylation in order to reverse the malignant phenotypes of these leukemias, and improve prognosis. Since MLL-rearranged infant ALL patients are even more hypermethylated at relapse, inhibition of aberrant DNA methylation might also be of vital importance at this stage of disease. Based on these data, we propose to initiate clinical trials using demethylating agents for patients with relapsed MLL- rearranged infant ALL. Meanwhile, we are investigating the in vitro cytotoxicity of various demethylating agents in our laboratory to pave the way for future clinical trials.

scholarly journals Global Modulation in DNA Epigenetics during Pro-Inflammatory Macrophage Activation

2019 ◽  
Author(s):  
Nikhil Jain ◽  
Tamar Shahal ◽  
Tslil Gabrieli ◽  
Noa Gilat ◽  
Dmitry Torchinsky ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Single Molecule ◽  
Transcriptional Control ◽  
Excision Repair ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Cell Types ◽  
Inflammatory Activation ◽  
Methylation Patterns

AbstractDNA methylation patterns create distinct gene expression profiles. These patterns are maintained after cell division, thus enabling the differentiation and maintenance of multiple cell types from the same genome sequence. The advantage of this mechanism for transcriptional control is that chemical-encoding allows to rapidly establish new epigenetic patterns “on-demand” through enzymatic methylation and de-methylation of DNA. Here we show that this feature is associated with the fast response of macrophages during their pro-inflammatory activation. By using a combination of mass spectroscopy and single-molecule imaging to quantify global epigenetic changes in the genomes of primary macrophages, we followed three distinct DNA marks (methylated, hydroxymethylated and unmethylated), involved in establishing new DNA methylation patterns during pro-inflammatory activation. The observed epigenetic modulation together with gene expression data generated for the involved enzymatic machinery, may suggest that de-methylation upon LPS-activation starts with oxidation of methylated CpGs, followed by excision-repair of these oxidized bases and their replacement with unmodified cytosine.

Xenografts of Pediatric Acute Lymphoblastic Leukemia Retain the Gene Expression Pattern From the Diagnostic Material They Originated From Over Serial Passages.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1629-1629
Author(s):  
Manon Queudeville ◽  
Elena Vendramini ◽  
Marco Giordan ◽  
Sarah M. Eckhoff ◽  
Giuseppe Basso ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bone Marrow ◽  
Bone Marrow Cells ◽  
Expression Profiles ◽  
Lymphoblastic Leukemia ◽  
Gene Expression Profiles ◽  
Leukemia Cells ◽  
Diagnostic Samples ◽  
Xenotransplantation Model

Abstract Abstract 1629 Poster Board I-655 Primary childhood acute lymphoblastic leukemia (ALL) samples are very difficult to culture in vitro and the currently available cell lines only poorly reflect the heterogeneous nature of the primary disease. Many groups therefore use mouse xenotransplantation models not only for in vivo testing but also as a means to amplify the number of leukemia cells to be used for various analysis. It remains unclear as to what extent the xenografted samples recapitulate their respective primary leukemia. It has been suggested for example that transplantation may result in the selection of a specific clone present only to a small amount in the primary diagnostic sample. We used a NOD/SCID xenotransplantation model and injected leukemia cells isolated from fresh primary diagnostic material of 4 pediatric ALL patients [2 pre-B-ALL, 1 pro-B-ALL (MLL/AF4}, 1 cortical T-ALL] intravenously into the lateral tail vein of unconditioned mice. As soon as the mice presented clinical signs of leukemia, leukemia cells were isolated from bone marrow and spleen. Isolated leukemia cells were retransplanted into secondary and tertiary recipients. RNA was isolated from diagnostic material and serial xenograft passages and gene expression profiles were obtained using a human whole genome array (Affymetrix U133 2.0). Simultaneously, immunophenotypic analysis via multicolor surface and cytoplasmatic staining by flow cytometry was performed for the diagnostic samples and respective serial xenograft passages. In an unsupervised clustering analysis the diagnostic sample of each patient clustered together with the 3 derived xenograft samples, although the 3 xenograft samples clustered stronger to each other than to their respective diagnostic sample. Comparison of the 4 diagnostic samples vs. all xenograft samples resulted in a gene list of 270 genes upregulated at diagnosis and 8 genes upregulated in the xenograft passages (Wilcoxon, p< .05). The high number of genes upregulated at diagnosis is most likely due to contamination of primary patient samples with normal peripheral blood and/or bone marrow cells as 15% of genes are attributed to myeloid cells, 7% to erythroid cells, 7% to lymphoid cells, 32% to bone marrow in general as well as to innate immunity, chemokines, immunoglobulins. The remaining genes can not be attributed to a specific hematopoetic cell lineage and are not known to be related to leukemia or cancer in general. Accordingly, there are no statistically significant differences between the primary, secondary and tertiary xenograft passages. The immunophenotype analysis are also in accordance with these findings, as the diagnostic blast population retains its immunophenotypic appearance during serial transplantation, whereas the contaminating CD45-positive non- leukemic cells disappear after the first xenograft passage. The few genes upregulated in xenograft samples compared to diagnosis are mainly involved in cell cycle regulation, protein translation and apoptosis resistance. Some of the identified genes have already been described in connection with cancer subtypes, their upregulation therefore being indicative of a high proliferative state in general and could argue towards a more aggressive potential of the engrafted leukemia cells but alternatively could also simply be due to the fact that the xenograft samples are pure leukemic blasts and are not contaminated with up to 15% of non-cycling healthy bone marrow cells as in the diagnostic samples. We conclude that the gene expression profiles generated from xenografted leukemias are very similar to those of their respective primary leukemia and moreover remain stable over serial retransplantation passages as we observed no statistically significant differences between the primary, secondary and tertiary xenografts. The differentially expressed genes between diagnosis and primary xenotransplant are most likely to be due to contaminating healthy cells in the diagnostic samples. Hence, the NOD/SCID-xenotransplantation model recapitulates the primary human leukemia in the mouse and is therefore an appropriate tool for in vivo and ex vivo studies of pediatric acute leukemia. Disclosures No relevant conflicts of interest to declare.

Specific promoter methylation identifies different subgroups of MLL-rearranged infant acute lymphoblastic leukemia, influences clinical outcome, and provides therapeutic options

Blood ◽  
2009 ◽  
Vol 114 (27) ◽  
pp. 5490-5498 ◽  
Author(s):  
Dominique J. P. M. Stumpel ◽  
Pauline Schneider ◽  
Eddy H. J. van Roon ◽  
Judith M. Boer ◽  
Paola de Lorenzo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Acute Lymphoblastic Leukemia ◽  
Clinical Outcome ◽  
Cpg Island ◽  
Lymphoblastic Leukemia ◽  
Promoter Hypermethylation ◽  
Aberrant Dna Methylation ◽  
Methylation Patterns ◽  
Infant Acute Lymphoblastic Leukemia

Abstract MLL-rearranged infant acute lymphoblastic leukemia (ALL) remains the most aggressive type of childhood leukemia, displaying a unique gene expression profile. Here we hypothesized that this characteristic gene expression signature may have been established by potentially reversible epigenetic modifications. To test this hypothesis, we used differential methylation hybridization to explore the DNA methylation patterns underlying MLL-rearranged ALL in infants. The obtained results were correlated with gene expression data to confirm gene silencing as a result of promoter hypermethylation. Distinct promoter CpG island methylation patterns separated different genetic subtypes of MLL-rearranged ALL in infants. MLL translocations t(4;11) and t(11;19) characterized extensively hypermethylated leukemias, whereas t(9;11)-positive infant ALL and infant ALL carrying wild-type MLL genes epigenetically resembled normal bone marrow. Furthermore, the degree of promoter hypermethylation among infant ALL patients carrying t(4;11) or t(11;19) appeared to influence relapse-free survival, with patients displaying accentuated methylation being at high relapse risk. Finally, we show that the demethylating agent zebularine reverses aberrant DNA methylation and effectively induces apoptosis in MLL-rearranged ALL cells. Collectively these data suggest that aberrant DNA methylation occurs in the majority of MLL-rearranged infant ALL cases and guides clinical outcome. Therefore, inhibition of aberrant DNA methylation may be an important novel therapeutic strategy for MLL-rearranged ALL in infants.

Identification of Gene Expression Profiles in Acute Lymphoblastic Leukemia Cells That Discriminate Intracellular Thioguanine Nucleotide Accumulation in ALL Cells after In Vivo Treatment with Mercaptopurine.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 453-453
Author(s):  
Gianluigi Zaza ◽  
Meyling Cheok ◽  
Wenjian Yang ◽  
Pei Deqing ◽  
Cheng Cheng ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bone Marrow ◽  
Acute Lymphoblastic Leukemia ◽  
Expression Profiles ◽  
Lymphoblastic Leukemia ◽  
Gene Expression Profiles ◽  
Post Treatment ◽  
Leukemia Cells ◽  
True Positive

Abstract Thioguanine nucleotides (TGN) are considered the principal active metabolites exerting the antileukemic effects of mercaptopurine (MP). Numerous clinical studies have reported substantial inter-patient variability in intracellular TGN concentrations during continuation therapy of acute lymphoblastic leukemia (ALL). To identify genes whose expression is related to the intracellular accumulation of TGN in leukemia cells after in vivo treatment with MP alone (MP) or in combination with MTX (MP+MTX), we used oligonucleotide microarrays (Affymetrixâ HG-U95Av2) to analyze the expression of approximately 9,670 genes in bone marrow leukemic blasts obtained at diagnosis from 82 children with ALL. TGN levels were determined in bone marrow aspirates of these patients 20 hours after mercaptopurine infusion (1 g/m2 I.V). Because, as previously reported, patients treated with MP alone achieved higher levels of intracellular TGN compared to those treated with the combination, we used Spearman’s rank correlation to identify genes associated with TGN levels separately for the 33 patients treated with MP alone and the 49 with the combination (MP: median TGN: 2.46 pmol/5x106 cells, range: 0.01–19.98; and MTX+MP: median TGN: 0.55 pmol/5x106 cells, range: 0.005–3.31). Hierarchical clustering using these selected probe sets clearly separated the 33 patients treated with MP alone into two major groups according to TGN concentration (< 2.46 and > 2.46 pmol/5x106 cells; n=60 genes) and two major branches were also found for patients treated with the combination (< 0.55 and > 0.55 pmol/5x106 cells; n=75 genes). Interestingly, there was no overlap between the two sets of genes, indicating that different genes influence the accumulation of TGN when this drug is given alone or in combination with MTX. The association between gene expression profiles and TGN levels determined by leave-one-out cross-validation using support vector machine (SVM) based on Spearman correlation, was rho=0.60 (p<0.001) for MP alone and rho=0.65 (p<0.001) for MTX+MP, with false discovery rate (FDR) computed using Storey’s q-value (MP: 50% true positive, MTX+MP: 70% true positive respectively). Genes highly associated with the post-treatment TGN level in ALL patients treated with MP alone encode transporters, enzymes involved in the MP metabolic pathway and cell proliferation. Genes associated with post-treatment levels of TGN after combined therapy have been implicated in protein and ATP biosynthesis. Together, these in vivo data provide new insights into the basis of inter-patient differences in TGN accumulation in ALL cells, revealing significant differences between treatment with MP alone or in combination with MTX.

scholarly journals Integrative Analysis of DNA Methylation and Gene Expression Profiles Identifies Colorectal Cancer-Related Diagnostic Biomarkers

2021 ◽  
Vol 27 ◽  
Author(s):  
Mingyue Xu ◽  
Lijun Yuan ◽  
Yan Wang ◽  
Shuo Chen ◽  
Lin Zhang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Colorectal Cancer ◽  
Dna Methylation ◽  
Logistic Regression Model ◽  
Cpg Island ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Training Set ◽  
Diagnostic Biomarkers ◽  
Cpg Sites

Background: Colorectal cancer (CRC) is a common human malignancy worldwide. The prognosis of patients is largely frustrated by delayed diagnosis or misdiagnosis. DNA methylation alterations have been previously proved to be involved in CRC carcinogenesis.Methods: In this study, we proposed to identify CRC-related diagnostic biomarkers by analyzing DNA methylation and gene expression profiles. TCGA-COAD datasets downloaded from the Cancer Genome Atlas (TCGA) were used as the training set to screen differential expression genes (DEGs) and methylation CpG sites (dmCpGs) in CRC samples. A logistic regression model was constructed based on hyper-methylated CpG sites which were located in downregulated genes for CRC diagnosis. Another two independent datasets from the Gene Expression Omnibus (GEO) were used as a testing set to evaluate the performance of the model in CRC diagnosis.Results: We found that CpG island methylator phenotype (CIMP) was a potential signature of poor prognosis by dividing CRC samples into CIMP and noCIMP groups based on a set of CpG sites with methylation standard deviation (sd) &gt; 0.2 among CRC samples and low methylation levels (mean β &lt; 0.05) in adjacent samples. Hyper-methylated CpGs tended to be more closed to CpG island (CGI) and transcription start site (TSS) relative to hypo-methylated CpGs (p-value &lt; 0.05, Fisher exact test). A logistic regression model was finally constructed based on two hyper-methylated CpGs, which had an area under receiver operating characteristic curve of 0.98 in the training set, and 0.85 and 0.95 in the two independent testing sets.Conclusions: In conclusion, our study identified promising DNA methylation biomarkers for CRC diagnosis.

Distinct Methylation Patterns among Infants with MLL Rearranged Acute Lymphoblastic Leukemia.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2794-2794
Author(s):  
Dominique J.P.M. Stumpel ◽  
Pauline Schneider ◽  
Eddy H.J. van Roon ◽  
Judith M. Boer ◽  
Renee X. Menezes ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bone Marrow ◽  
Acute Lymphoblastic Leukemia ◽  
Cpg Island ◽  
Lymphoblastic Leukemia ◽  
Methylation Pattern ◽  
Unique Type ◽  
Genome Wide ◽  
Pediatric All ◽  
Methylation Patterns

Abstract Acute Lymphoblastic Leukemia (ALL) in infants (i.e. children <1 year of age) is characterized by a high incidence of rearrangements of the MLL gene (∼80%) which is associated with a poor prognosis. The most frequent MLL rearrangements in infant ALL are translocations t(4;11), t(11;19) and t(9;11). Recently, gene expression profiling has established MLL rearranged leukemia as a unique type of leukemia (denoted MLL), that is clearly distinguishable from other ALL subtypes. Currently, these gene expression profiles are slowly revealing important genetic properties underlying this aggressive type of leukemia, however, any epigenetic data on MLL are still lacking. Therefore, the present study was designed to unravel the MLL-specific methylation patterns underlying infant MLL by applying differential methylation hybridization (DMH) using CpG island microarrays containing ∼9000 CpG island probes, in duplicate. Primary infant ALL samples carrying t(4;11) (n=21), t(11;19) (n=17) and t(9;11) (n=6) were compared to infant ALL (n=13) and non-infant pediatric ALL (n=15) samples without MLL rearrangements. In addition, healthy pediatric bone marrow samples (n=9) were included as a reference. Compared to healthy controls, 656 CpG island probes were identified as significantly hypermethylated in t(4;11) positive samples, and 131 CpG island probes in t(11;19) positive samples (p<0.01, false discovery rate <5%). Interestingly, t(11;19) positive ALL patients shared 95% of their methylated probes with t(4;11) patients, suggesting a common methylation pattern which is completely absent in both infant and non-infant ALL patients lacking MLL rearrangements. Remarkably, displaying only a single probe significantly methylated as compared to healthy bone marrow, this common methylation pattern is also absent in t(9;11) positive ALL patients, indicating that based on genome-wide methylation, these patients represent a distinct entity clearly distinguishable from other MLL subgroups. Moreover, the fact that t(4;11) patients exhibit 532 methylated CpG island probes that were not found to be methylated in t(11;19) patients, demonstrates that these patients also exhibit a t(4;11) specific set of methylated genes. Identification of the genes represented by these CpG island probes and subsequent validation of the results obtained in this study is currently being performed (using pyrosequencing and methylation specific PCR analyses). In conclusion, these data reveal that different types of MLL rearranged infant ALL show distinct genome-wide methylation patterns. Specifically, infant ALL patients carrying t(4;11) and t(11;19) are characterized by severe CpG island hypermethylation, as compared to both t(9;11) positive infant ALL patients, as well as pediatric ALL patients lacking MLL rearrangements. Therefore, t(4;11) and t(11;19) patients in particular may well be suitable candidates for DNA methylation inhibiting therapeutic intervention. Finally, these promising results for the first time provide epigenetic insights into the complex biology of infant MLL, and clearly warrant further investigation currently being performed at our laboratory.

Changing Gene Expression Patterns during Early Treatment of B-Precursor Acute Lymphoblastic Leukemia May Be Predictive of Relapse.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 232-232 ◽  
Author(s):  
Valerie de Haas ◽  
Rob Dee ◽  
Goedele Cheroutre ◽  
Henk van den Berg ◽  
Huib Caron ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bone Marrow ◽  
Acute Lymphoblastic Leukemia ◽  
Cell Lines ◽  
Expression Profiles ◽  
Lymphoblastic Leukemia ◽  
Gene Expression Profiles ◽  
Expression Level ◽  
Leukemic Cells ◽  
Diagnostic Samples

Abstract Treatment of pediatric ALL is based on the concept of tailoring the intensity of treatment to a patients risk. Clinical studies have shown that it is possible to stratify patients according to the levels of minimal residual disease after induction therapy and early during further treatment, since it has been demonstrated that the MRD level is the best predictive level for disease outcome. More recently, it has been shown that gene expression profiles of leukemic cells at diagnosis might be correlated with outcome. In previous studies we reported that slow responding subclones represent the clones causative for a leukemic relapse in oligoclonal disease. Based on these results, we hypothesized that the gene expression profile of the slow responding subclones present after the first weeks of chemotherapy might be more predictive than the profiles of all leukemic cells at diagnosis. Twenty-four genes were selected; most signalling molecules, transcription factors and functions relevant for oncogenesis, drug resistance and metastasis. Selection of genes was based on the presently available data on prognostic cDNA microarry studies of cytogenetically defined subgroups of childhood ALL. In particular, we analyzed results of recently published studies that compared gene expression levels between diagnosis and relapse in B-precusor acute lymphoblastic leukemia. (Staal, 2003 and Beesley, 2005). Gene sequences were obtained from public databases. Genes were tested on different leukemic cell lines. For all cell lines differences in gene expression level were demonstrated. The same panel of genes was tested on diagnostic samples of 16 ALL patients, subsequently followed by investigation of paired diagnosis - day 15 - relapse samples of 3 relapsed ALL patients. Leukemic material was obtained from cryopreserved bone marrow samples. All leukemic cells were purified by MACS purification based on markers expressed on the tumour, i.e. CD34, CD19 and CD10. RNA extraction and cDNA synthesis was performed according to the TRIZOL protocol. Expression levels were determined in a SYBR Green based real-time PCR assay. We were able to show different gene expression profiles in the 16 tested diagnostic samples. For the paired samples from relapsed B-precursor ALL patients, the expression level of several genes at day 15 was different (ΔCT&gt;1) in regard to diagnosis. Moreover, the changed expression at day 15 was comparable to the expression level of this gene at relapse. We conclude that indeed we were able to demonstrate that some of the genes have a changing pattern of expression during early therapy (day15), a pattern which is comparable to the pattern of gene expression at relapse and which is different from the pattern at diagnosis. We also demonstrated that purification of the bone marrow samples is necessary to be certain that the gene expression shown is relevant for the leukemic cells and not contaminated by other cells, i.e. T-cells. Figure Figure

scholarly journals Age-related differences in monocyte DNA methylation and immune function in healthy Kenyan adults and children

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Katherine R. Dobbs ◽  
Paula Embury ◽  
Emmily Koech ◽  
Sidney Ogolla ◽  
Stephen Munga ◽  
...  
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Young Adults ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Innate Immune ◽  
Inflammatory Gene Expression ◽  
Cpg Sites ◽  
Age Related ◽  
Adults And Children

Abstract Background Age-related changes in adaptive and innate immune cells have been associated with a decline in effective immunity and chronic, low-grade inflammation. Epigenetic, transcriptional, and functional changes in monocytes occur with aging, though most studies to date have focused on differences between young adults and the elderly in populations with European ancestry; few data exist regarding changes that occur in circulating monocytes during the first few decades of life or in African populations. We analyzed DNA methylation profiles, cytokine production, and inflammatory gene expression profiles in monocytes from young adults and children from western Kenya. Results We identified several hypo- and hyper-methylated CpG sites in monocytes from Kenyan young adults vs. children that replicated findings in the current literature of differential DNA methylation in monocytes from elderly persons vs. young adults across diverse populations. Differentially methylated CpG sites were also noted in gene regions important to inflammation and innate immune responses. Monocytes from Kenyan young adults vs. children displayed increased production of IL-8, IL-10, and IL-12p70 in response to TLR4 and TLR2/1 stimulation as well as distinct inflammatory gene expression profiles. Conclusions These findings complement previous reports of age-related methylation changes in isolated monocytes and provide novel insights into the role of age-associated changes in innate immune functions.

scholarly journals Multiple Myeloma Cells Alter Adipogenesis, Increase Senescence-Related and Inflammatory Gene Transcript Expression, and Alter Metabolism in Preadipocytes

2021 ◽  
Vol 10 ◽  
Author(s):  
Heather Fairfield ◽  
Samantha Costa ◽  
Carolyne Falank ◽  
Mariah Farrell ◽  
Connor S. Murphy ◽  
...  
Keyword(s):  
Gene Expression ◽  
Multiple Myeloma ◽  
Bone Marrow ◽  
Lipid Accumulation ◽  
Expression Profiles ◽  
Adipogenic Differentiation ◽  
Gene Expression Profiles ◽  
Mouse Bone Marrow ◽  
Gene Transcript ◽  
Bone Marrow Mscs

Within the bone marrow microenvironment, mesenchymal stromal cells (MSCs) are an essential precursor to bone marrow adipocytes and osteoblasts. The balance between this progenitor pool and mature cells (adipocytes and osteoblasts) is often skewed by disease and aging. In multiple myeloma (MM), a cancer of the plasma cell that predominantly grows within the bone marrow, as well as other cancers, MSCs, preadipocytes, and adipocytes have been shown to directly support tumor cell survival and proliferation. Increasing evidence supports the idea that MM-associated MSCs are distinct from healthy MSCs, and their gene expression profiles may be predictive of myeloma patient outcomes. Here we directly investigate how MM cells affect the differentiation capacity and gene expression profiles of preadipocytes and bone marrow MSCs. Our studies reveal that MM.1S cells cause a marked decrease in lipid accumulation in differentiating 3T3-L1 cells. Also, MM.1S cells or MM.1S-conditioned media altered gene expression profiles of both 3T3-L1 and mouse bone marrow MSCs. 3T3-L1 cells exposed to MM.1S cells before adipogenic differentiation displayed gene expression changes leading to significantly altered pathways involved in steroid biosynthesis, the cell cycle, and metabolism (oxidative phosphorylation and glycolysis) after adipogenesis. MM.1S cells induced a marked increase in 3T3-L1 expression of MM-supportive genes including Il-6 and Cxcl12 (SDF1), which was confirmed in mouse MSCs by qRT-PCR, suggesting a forward-feedback mechanism. In vitro experiments revealed that indirect MM exposure prior to differentiation drives a senescent-like phenotype in differentiating MSCs, and this trend was confirmed in MM-associated MSCs compared to MSCs from normal donors. In direct co-culture, human mesenchymal stem cells (hMSCs) exposed to MM.1S, RPMI-8226, and OPM-2 prior to and during differentiation, exhibited different levels of lipid accumulation as well as secreted cytokines. Combined, our results suggest that MM cells can inhibit adipogenic differentiation while stimulating expression of the senescence associated secretory phenotype (SASP) and other pro-myeloma molecules. This study provides insight into a novel way in which MM cells manipulate their microenvironment by altering the expression of supportive cytokines and skewing the cellular diversity of the marrow.

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